73 
observed several have been mentioned in other members of this 
family. For this reason it is hardly necessary to make some 
preliminary remarks, the less so because Prof. Pxnzie in his 
»Pflanzenteratologie II p. 324 sqq. and in his ,Considérations 
sur les anomalies des Orchidées” ') has published an excellent 
survey of the principal monstrosities. We take from Prnzic 
only the so well marked difference between dimery and pseudo- 
dimery in the structure of the flower. When the flower is di- 
merous, both calyx and corolla show the number 2 instead of 
3, the sepals being placed transverse and the petals (of which 
one is the labellum) median. In pseudo-dimerous flowers however 
the inferior sepals have grown together to an apparently simple 
one which is opposed to the third sepal. The ordinary petals 
are in this case placed transverse, while the labellum is absent. 
The latter kind of dimery (Prnzic distinguishes other forms be- 
sides?)) presents itself with perfect distinctness in the Giant-Orchid, 
Grammatophyllum speciosum, of which I have given an ample 
description in the ,Botanisch Jaarboek” edited by Doponaza, 
Ghent, 1894, p. 24. The peculiarity of this plant consists in the 
pseudo-dimery of the lower flowers of the inflorescence against 
the trimery of the much more numerous flowers higher up. The 
same phenomenon has been also found in a couple of other 
Orchidaceae, which we will deal with further on. For the rest 
we shall find that several cases have been collected by Mr. Suita 
of reversion of stamens in the place where the theory of the 
floral structure requires them either latent or transformed. 
In order to prevent misunderstanding we beg to say that in 
our descriptions we represent the flower in its position after 
the resupination or the torsion. 
Arundina speciosa Bl. 
Habitat Southern Asia. 
Coll. Dec. 1895. 
Dimerous flower. 
1) Mémoires de la Société nationale des Sciences naturelles et mathématiques de 
Cherbourg, Tome XXIX, 1894. 
2) Compare the description of Chrysoglossum ornatum p. 74. 
